Anesthesiology APPLIED Exam › Endocrine, renal, hepatic and metabolic

Pheochromocytoma

Endocrine, renal, hepatic and metabolic·~5 min read· Physician-reviewed✓ Sourced · 4

Stem

A 44-year-old woman, 64 kg, with episodic headaches, palpitations and sweating has a 5 cm left adrenal mass and elevated plasma metanephrines. She is scheduled for laparoscopic left adrenalectomy in two weeks. Clinic blood pressure is 168/102, heart rate 98, and she has no other medical history. The surgeon asks what you need before the day of surgery.

Question

How will you prepare her, and how will you manage the anesthetic through tumor removal?

Ideal answer

HeadlineAdequate alpha blockade first: 7–14 days of phenoxybenzamine or doxazosin, because an unblocked patient has a constricted, empty vascular tree and dies of hypertensive stroke or post-resection collapse.

Alpha-block to Endocrine Society targets, with high-salt diet and fluids: seated pressure below 130/80, standing systolic above 90, heart rate 60–70 seated and 70–80 standing.¹
Beta blockade follows alpha, never precedes it,¹ as unopposed alpha causes hypertensive crisis.
Arterial line before induction, central line for infusions; deep induction: propofol, generous opioid, lidocaine to blunt laryngoscopy.
Nitroprusside, nicardipine, esmolol and magnesium ready for insufflation and tumor handling.
Warned before the adrenal vein is clamped, I stop vasodilators ahead of it, phenylephrine, norepinephrine, vasopressin and several liters of crystalloid primed: pressure can fall from 220 to 60 within a minute.

Watch for: hypoglycemia and hypotension, postoperatively in a monitored bed.

Breaking down the answer

Phenoxybenzamine or doxazosin — phenoxybenzamine is irreversible and non-selective, the most reliable blockade, at the cost of reflex tachycardia and postoperative hypotension; doxazosin is selective and shorter-acting. Changes if: a large tumor with wild pressures gets phenoxybenzamine, a routine adenoma doxazosin.
Add-ons, older targets — calcium-channel blockers are the add-on when pressure is uncontrolled, not a substitute.¹ Classic Roizen criteria (below 160/90, standing no lower than 80/45, no ST changes, under one ectopic beat every five minutes) are an older target.
Beta only after alpha — unopposed beta blockade removes beta-2 vasodilation and leaves alpha constriction uncontested. A beta-blocker only for tachycardia after at least 3–4 days of alpha; labetalol is not initial therapy because its alpha effect is weak.¹
Volume loading — chronic vasoconstriction contracts plasma volume; 1–2 L of saline from the evening before surgery,¹ because after ligation she needs a full tank, not a pressor alone.
Drugs I avoid — succinylcholine fasciculations compress the tumor; ketamine, ephedrine and pancuronium release or mimic catecholamines; metoclopramide and droperidol provoke release; morphine and atracurium release histamine. I use propofol, fentanyl or remifentanil, rocuronium and sevoflurane.
Vasodilator choice — nitroprusside acts in seconds and is gone in minutes; nicardipine is safer in less experienced hands but lingers; magnesium, 50 mg/kg then 15 mg/kg/h, blunts release and arrhythmias;² phentolamine 1–5 mg boluses work but tachyphylaxis limits it.
Laparoscopy — insufflation itself provokes catecholamine release, so I ask for the lowest workable pressure and expect a surge before the gland is touched.

Follow-up question

The surgeon grasps the tumor and the pressure climbs to 240/130 with ventricular ectopy. Ten minutes after you control it, the vein is tied and the pressure reads 65/30, unresponsive to phenylephrine. How do you manage each phase?

Follow-up answer

HeadlineA handling surge, then catecholamine withdrawal after ligation. First I tell the surgeon to stop handling the gland.

I deepen the anesthetic, start or escalate nitroprusside (average effective rate about 3 mcg/kg/min),³ give magnesium 50 mg/kg over 30 min, and add esmolol 0.5 mg/kg for tachycardia and ectopy. I watch ST segments for ischemia or pulmonary edema, then the surgeon continues in smaller steps. After ligation: vasodilators off, 500 mL boluses, which are first-line,⁴ then norepinephrine and vasopressin, because downregulated alpha receptors respond poorly and vasopressin acts through a separate receptor. I reassess pressure and check glucose. An undiagnosed tumor gets the same treatment, and I ask the surgeon to abort once stable.

Pitfalls that cost points

Describing the induction before saying the patient was alpha-blocked and volume-loaded: the examiner tests the preparation.
Running nitroprusside through the ligation, then wondering why the pressure will not come up.
Reaching for ephedrine, which releases catecholamines from a tumor that has plenty.

Rapid-fire

Q: Why does hypoglycemia occur after resection? A: Catecholamines suppress insulin and drive glycogenolysis; when they vanish, insulin rebounds, in about 5–15% of patients, usually within 4 hours; I monitor glucose and hemodynamics for 24–48 hours.⁴^,1

Q: What else looks like this under anesthesia? A: Light anesthesia, malignant hyperthermia, thyroid storm, carcinoid and autonomic hyperreflexia; a rising end-tidal CO2 points toward MH.

Q: Why is an epidural not enough to prevent the surge? A: It removes sympathetic nervous output but not catecholamines pouring from the tumor into the blood, and it adds to post-ligation hypotension.

Q: Which syndromes carry a pheochromocytoma? A: MEN 2A and 2B, von Hippel-Lindau and neurofibromatosis type 1; in MEN 2 I ask about medullary thyroid carcinoma and hyperparathyroidism.

Numbers to know

Item	Value
Alpha blockade duration	7–14 days before surgery¹
Endocrine Society targets	Seated BP <130/80, standing SBP >90, HR 60–70 seated, 70–80 standing¹
Roizen criteria (classic)	BP <160/90, orthostasis not below 80/45, no ST changes, <1 PVC per 5 min
Nitroprusside	Start 0.3 mcg/kg/min; max 10 mcg/kg/min for ≤10 min; cyanide accumulates above 2 mcg/kg/min³
Phentolamine	1–5 mg IV boluses
Magnesium	50 mg/kg over 30 min (3.2 g for her), then 15 mg/kg/h (about 1 g/h)²
Postoperative hypoglycemia	5–15%, usually within 4 h⁴

Sources

1.Pheochromocytoma and Paraganglioma: An Endocrine Society Clinical Practice Guideline · Endocrine Society, 2014 · richtlijnendatabase.nlLenders et al., JCEM 2014. Recommendations 4.1–4.3 and Table 9.
2.Pheochromocytoma Across the Perioperative Course: Current Concepts and Clinical Management · Anesthesiology Research and Practice (Mirrakhimov, Bashall, Sengupta), 2026 · europepmc.orgTable 6: magnesium loading dose 50 mg/kg over 30 min, then 15 mg/kg/h.
3.Nitropress (sodium nitroprusside) prescribing information · FDA label (Drugs.com) · drugs.com
4.Update on Pheochromocytoma and Paraganglioma from the SSO Endocrine and Head and Neck Disease Site Working Group, Part 2: Perioperative Management and Outcomes · Annals of Surgical Oncology (SSO), 2020 · pmc.ncbi.nlm.nih.gov

Facts on this page were checked against these sources on Oct 14, 2026. Guidelines change; confirm doses against current institutional protocols.